Flame and fireproofing of textile materials



Patented Feb 4, 1%?

FLAME AND mnnraoornvo or rexme Marenms George W. Seymour and George C. Ward, Cumberland, MdL, assignors to Celanese Corporation of America, a corporation of Delaware No Drawing. Application January 27, 1943,

Serial No. 473,702

l invention relates to the treatment of textlle materials, and relates more particularly to the treatment of textile materials. made of or containing cellulose acetate or other organic derivative of cellulose in order to make the same name and fire-proof.

It is an important object of this invention to provide a novel, method of rendering flameand fire-proof textile materials made of or containing cellulose acetate or other organic derivative of cellulose.

Another object of this invention is the provislon of a novel treatment for textile materials made oi? or containing cellulose acetate or other organic derivative of cellulose which prevents dripping when said textile materials are exposed to flame.

a further object of this invention is the provislon of improved textile materials made of or containing cellulose acetate or other organic derivative of cellulose which will not cause spread:-

ing of lire should said materials come in contact with an open flame.

Other objects of this invention will appear from the following detailed description.

Textile materials made of or containing organic derivatives of'ccllulose-are relatively dimcult of rendering flameor fire-proof. While or 3 Uiainis. (Cl. 117-137) tion may contain certain swelling or penetrating agents for the cellulose acetate or other organic" derivative of cellulose material being treated.

which may be employed are thiocyanates, for example, ammonium thiocyanate, sodium thiocya-.

' nate or barium thiocyanate. or other swelling and penetrating agents for organic derivative of cellulose materials, such as ethyl lactate or thiourea.

When flreproofing fabrics having a. basis of cellulose acetate or other organic derivative of cellulose in accordance with our invention, we have found that an excellent hand may be imparted to said fabrics if an alkyl-substituted diammonium phosphate is present in the aqueous or aqueous-alcoholic solution in addition to the other agents employed in the flameand fireproofing treatment. Examples of the dlammonium alkyl phosphates which may be employed are diammonium methyl phosphate, diammonium ethylphosphate, diammonium amyl phosphate and diammonium octyl phosphate. Diammonium garlic derivatives of cellulose are not considered highly inflammable, they may be ignited. Moreover; there is present in the use of such materials the added danger that drops of molten or- I ganic derivative of cellulose material may ignite other inflammable materials.

We have now discovered that cellulose acetate or other organic derivative of cellulose textile Inaterials in the form of yarns, fabrics, staple fiber, etc., may be rendered not only fire-proof but non-dripping aswell if said textile materials are treated with a solution of urea and an ammonium salt in an aqueous or aqueous-alcoholic solvent medium, and the solvent medium is removed. The removal of the solvent medium by any 001).".

venient drying process permits the urea and ammonium salt to remain thereon and the treated textile materials thus obtained exhibit unusually desirable fire-resisting qualities. As examples of .diammonium alkyl phosphate.

methyl phosphate is preferably employed, however.

Varying concentration of the fire-proofing agents may be present in the aqueous or aqueousalcoholic solutions from which they are applied. The urea may be employed in amounts of from 5 to 30% on the weight of the solution but preferably the solutions employed contain from 10 to 15% by weight of urea. The concentration of the ammonium salts may be from 5 to 25% by weight of the solution, but optimum results are achieved when the'solution contains from 10 to l5%'by weight of the ammonium salt.

When diammonium alkyl phosphates are al plled together with'the fire-proofing agents to produce a softer and more desirable hand in fab rics, excellent results may be obtained when the solution contains from 2 to 40% by weight of the Preferably, we employ solutions containing 15 to 25% by weight of the diammonium alkyl phosphate. If aqueous-alcoholic solutions are employed as. the solvent for the fire-proofing agents, the alco-i hol mayncomprise from 15 to 75% by weight of the solvent.

the ammonium salts which may be employed in carrying out our novel fire-proofing treatment there may be mentioned ammonium bromide, ammonium chloride, ammonium borate and diammonium phosphate. The most desirable re- The quantity of said fire-proofing agents applied to the textile materials will, of course, vary depending upon the textile material and the degree of fireprooflng desired. We have found that suits are achieved, however, employing ammonium bromide. v

hesidcs urea and an ammonium salt the solusatisfactory results are obtained when the weight of the textile material is increased from about 20 to 45% by thetreatment. To attain this weight increase the fire-proofing solution may be proofing treatment.

applied to the textile material by 2. padding or immersion treatment which maycomprise processing the textile material with the fire-proofing solution one, two or even three or more times. After treatment, the textile material may be dried in any convenient manner, but a a hot tower or tenter frame is preferably employed for fabrics.

In addition to the softening agents added to improve the hand of the treated material, the

. solution may also contain waterproofing agents.

By employing such solutions a showerproofing of the material as well as a fire-proofing may be effected in but a single treatment.

In order further to illustrate our invention but without being limited thereto, the following examples are given:

Example I An aqueous solution comprising 20% by weight of diammonium methyl phosphate, by weight of ammonium bromide and by weight of urea is padded On to a cellulose acetate fabric and the latter is dried in a hot tower. The fabric is increased in weight by 45% by this fire- The dried fabric is tested for its fire-proof qualities by placing samples of the fabric in the open luminous flame of a Bunsen burner. The fabric does not ignite but merely melts and chars 'without dripping, indicating that a very satisfactory degree of fire-resistance is.

imparted thereto by this treatment.

Example II of 34%. On being tested with an open flamethe staple is found to be fireproof.

Example III A cellulose acetate fabric is padded with aw solution comprising 75% ethyl alcohol and 25% water containing 15% by weight of ammonium bromide and 15% by'weight of urea, and dried in a hot tower. The fabric is rendered fireproof by this treatment. It may be given a somewhat softer hand if diammonium methyl phosphate is] added to the above solution.

- Example IV A cellulose acetate fabric ispadded with an aqueous solution containing 15% by weight of ammonium bromide and 15% by weight of urea. The padded fabric is dried on a tenter frame.-

On being tested with an open flame the fabric is found to be fireproof.

While our invention has been more particularly described in connection with the'treatment of textile materials having a basis of cellulose acetate, textile materials made of or containing other organic derivatives of'cellulose may also be rendered fire-proof in like manner by our novel treatment. Examples of other organic derivatives of cellulose are cellulose esters such as, cellulose propionate and cellulose butyrate, mixed esters such as, cellulose acetate-propionate and cellulose acetate-butyrate, and cellulose ethers such as ethyl cellulose and benzyl cellulose.

I In addition to organic derivatives of cellulose, the textile materials treated in accordance with our novel process may contain yarns and fibers ,of other textile materials, such as, for example, cotton, wool or regenerated cellulose. By employing our process said mixed materials may also be rendered fiameand fire-proof.

It is to be understood that the foregoing detailed description is given merely by way of illustration and that many variations may be made therein without departing from the spirit of our invention.

Having described our invention, what we desire to secure by Letters Patent is:

1. Process for the treatment of textile materials having a basis of cellulose acetate to render the same flame-proof, fire-proof and drip proof, which comprises applying to a textile material having a basis of cellulose acetate a solutlon in an aqueous solvent medium comprising from 5 to 25% of ammonium bromide and from 5 to 30% of urea, and removing the water.

2.Process for the treatment of fabrics having a basis of cellulose acetate to render the same flame-proof. fire-proof and drip proof, which comprises applying to a fabric having a basis of cellulose acetate a solution inan aqueous solvent medium comprising from 5 to 25% of ammonium bromi from 5 to 40% of diammonium methyl phosphate and from 5 to 30% of urea, and removing the water.

3. Process 'for the treatment of fabrics having a basis of cellulose acetate to render the same flame-proof, fire-proof and drip-proof, which comprises applying to a fabric having a basis of cellulose acetate a solution in an aqueous solvent medium comprising 10% by weight oframmonium bromide, 20% by weight of diammofiium methyl phosphate, and 15% by weight of urea, and removing the water, whereby an increase in weight ofabout 45% is efiected.

GEORGE W. SEYMOUR. GEORGE C. WARD.

REFERENCES CITED The following references are of record in the file of'this patentr UNITED STATES PATENTS Number Name Date 2,262,634 Cobbs Nov. 11, 1941 2,097,509 Boiler Nov. 2, 1937 2,036,854 Dickie, etal 'Apr. 7, 1936 1,792,457 Arent Feb. 10, 1931 1,612,104 Eichengrun Dec. 28, 1926 1,315,216 Doerfiinger Sept. 9, 1919 2,071,345. Morgan Feb. 23, 1937 I FOREIGN PA'TTJNTS Number Country Date 175,746 British Feb. 20, 1922 

